1. Field of the Invention
The present invention relates to a laser welding method and a laser welding system.
2. Background Information
Conventionally, certain types of welding have been conducted using moving devices. In recent years, laser welding is also being conducted using moving devices. Such laser welding is conducted using a laser processing head having a lens or a mirror configured and arranged to focus a laser beam onto a surface of a workpiece. The processing head is configured and arranged to shine the laser beam onto the surface of the workpiece while being moved by a moving device. The laser beam welds the workpiece by imparting a prescribed amount of heat to the workpiece. Japanese Laid-Open Patent Publication No. 2003-251481 discloses such conventional laser welding system in which the moving device is temporarily stopped at a welding start point and a welding end point in order to position the laser processing head (i.e., to position the laser beam) with respect to a welding position, and the laser output of a laser oscillator is turned on in response to a synchronization signal from the moving device. When the laser output is turned on, the moving device is accelerating from the stop state and has not reached the speed required for welding. Thus, if welding is conducted at the beginning of the laser welding in the same manner as when the required speed has already been reached, the welding state will become unstable due to a severely high-output laser beam being shone onto a small surface area. Therefore, in the conventional laser welding system, for example, the waveform of the laser output is controlled in an attempt to stabilize the weld quality at the bead ends.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved laser welding method and laser welding system. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.